Clamp



June 1,1943. F C, WALLACE '2,320,493

CLAMP Filed Jam 9' 1942 Patented June 1, 1943 CLAMP Frank C. Wallace,Los Angeles, Calif., assigner, by mesne assignments, to Herman H.Helbush,

Beverly Hills, Calif.

Application January 9, 1942, Serial No. 426,228

7 Claims.

This invention has to do with clamping tools and more particularly itrelates to clamps used to temporarily hold superposed or overlappingperforated sheets together with their perforations in register tofacilitate riveting. This present invention concerns improvements in theretaining members employed in such clamps as are described and claimedin my copending application Serial No. 417,813, led November 4, 1941,and has for one of its principal objects the provision of a clampembodying a retaining member which may be installed and assembled withminimum time and effort and which, when assembled remains securely inposition.

These clamps are used by the hundreds of thousands in the airplaneindustry and necessarily must be capable of being manufacturedeconomically and yet be sufcently durable to withstand hard usage. Forinstance, in the clamp of my said copending application the spreadermember employed to spread apart the legs of the retaining member must beinserted from within the cylindric clamp body during assembly and theenlarged outer ends of the legs must be passed through the relativelysmall opening in the body and wall before the spreader is inser-ted. Atthe same time it is desirable to have the opposite ends :of the legsheaded to prevent the operating plunger in which the legs are mountedfrom escaping outwardly from the body and separating from the legs ofthe retaining member. This situation presents material assemblydifficulties unless it is possible to install the plunger afterinserting the retaining member and spreader through the relatively smallhole in the end wall of the clamp body and after inserting theretracting spring into the body yaround the retaining member. While Ihave shown one way of accomplishing this in my said eopendingapplication, I have found that the improvements of this presentapplication materially facilitate manufacture and assembly and alsoprovide an extremely durable construction.

Still further objects and advantages are inherent in my invention andhow those as well as the foregoing are attained will be made apparentfrom the following detailed description of a presently preferredadaptation thereof, for which purpose I refer to the accompanyingdrawing, in which:

Fig. 1 is a side elevation showing the clamp in course of being appliedto the work;

Fig. 2 is a longitudinal sectional View show- .ing the device inclamping position;

Fig. 3 is an end View taken on line' 3-3 of Fig. 2; and

Fig. 4 is a section on line 4-4 of Fig. 2.

Referring now to the drawing, the numeral 5 designates a cylindric bodyhaving an annular ilange 6 at one end to be engaged by a clamp applyingtool, not shown, and having an end wall l provided with a centralopening 8.

A plunger I0 having a central longitudinal bore and a reduced diameterinner end I5 is slidably mounted in the bore of the body, a coil springIl being interposed between the inner end of the plunger and the insertmember to be hereinafter described, the spring embracing the reduceddiameter portion l5 of the plunger.

A tubular insert 2D extends through opening S, this insert having anenlarged diameter cupshaped inner end 2| which rests inside the bodyagainst the inner surf-ace of end wall-1, being rotatable with respectto the body.

A retaining member comprised of parallel elongated legs 30 headed attheir inner ends 3| and having enlarged outer ends 32 is slidablymounted in the body so that the enlarged ends 32 may be protracted andretracted with respect thereto so as to be inserted through registeringperforations P in superposed sheets S for the applying and clampingoperations as more particularly described in my said copendingapplication. A T-shaped spreader is positioned between the legs 38 todiametrically spread them apart as the legs slide with respect to thespreader. This spreader has a cross yarm portion 40 which rests withinthe recess 22 provided in the inner end 2| of the insert and has acentral arm 4| which projects through opening 8 between legs 2G to apoint spaced outwardly from .the outer end of the insert 20. A washer 44is interposed between the inner end of spring |1 and the inner end 2| ofthe insert, the legs 3|! slidably passing :through the central hole 45in the washer. Thus while Ithe spreader arm 40 is free to rotateeoaxially in the recess 22, it is held against longitudinal movementbetween this washer and the insert. A dimple 4l is provided on the outersurface of the end wall around hole 8 whereby to engage in thecountersink C of perforation P.

To assemble my device, the insert 20 is rst inserted through the bodybore, after which the e retainer legs 30, with the washer 44 therearoundand positioned adjacent the headed end 3|, are inserted. Next thespreader is inserted and the washer pushed down against the inner end ofthe insert, after which the spring I1 is inserted in the.

body around the legs 21'). Then the plunger l0 is inserted against andsomewhat compressing the spring, the headed ends 3l of the retaininglegs passing upwardly through the bore l l of the plunger until theyreach the countersunk end ma of the plunger. I then secure the retainerlegs in the plunger by inserting a bar 50 between the headed ends of thelegs, which acts to spread the headed ends 3l diametrically apart tocause them to engage in the countersink Ilia and prevents the springfrom forcing the plunger outwardly with respect to the retaining legs.

When thus assembled the plunger is held against escape from the body bymeans of the enlarged ends 32 of the legs engaging against the cuter endof the insert 29, when the device is in inoperative or non-clampingposition, or by the enlarged ends 32 engaging against the sheet Sfarthest from the body end wall 1 when the device is in clampingposition (see position of Fig. 2).

While I have resorted to considerabledetail for the purpose of making myinvention understood, I wish it understood that'within its broaderscope, as defined by the appended claims, various modications andadaptations may be made without departing from the spirit of theinvention.

I claim:

1. In a clamp device, the combination of a body, a plunger slidablymounted therein, said plunger being provided with a bore, a retainingmember slidably mounted in the body, the inner end of the retainingmember being longitudinally split and disposed longitudinally of thebore in the plunger, and means for securing the retaining member in theplunger including a separator inserted in vthe longitudinally split'endof the retaining member.

2. In a clamp device, the combination -cf a body, a plunger slidablymounted therein, said plunger being provided with a longitudinal bore,the bore having an enlarged diameter portion, a retaining memberslidably mounted in the body and being protractable and retractable atits outer end with respect to the body, the inner end of the retainingmember being disposed longi tudinally of the bore inthe plunger andpresenting a lateral projection, andan -insert in the plunger engagingthe inner end of the retaining member whereby to engage said lateralprojection in said enlarged diameter portion.

3. In a clamp device, the combination of a body, a plunger slidablymounted therein, said plunger being provided with a longitudinal openingtherethrough, a retaining member having a split inner end mounted insaid longitudinal opening, and means spreading the inner end of theretaining member into engagementI with the side walls of the openingwhereby to secure the inner end oi the retaining member againstlongitudinal movement with respect to the plunger.

4. In a clamp device, a cylindric body, a plunger slidably mounted inthe body, said plunger being provided with a longitudinal openingtherethrough, a countersink in the opening, an elongated retainingmember disposed longitudinally of the body, the inner end of theretaining member presenting parallel legs disposed longitudinally insaid opening and each having a headed portion, means disposed betweensaid legs and diametrically spreading them apart whereby to engage saidheaded portions in said countersink, and a spring in the body, saidspring bearing against the plunger in a direction to resiliently resistlongitudinal escape of said headed portions from said countersink.

5. In a clamp device, the combination of a body, a plunger slidablymounted therein, said plunger being provided with an opening countersunkat its outer end, a retaining membercomprised of spaced parallel legsmounted longitudinally of the body, the inner ends of said legs beingdisposed longitudinally in the opening through the plunger and havingheaded portions adapted to engage in said countersink, and lan expanderbar inserted between said headed 'portions whereby to expand them intoengagement with the side walls of the countersink.

6. In a clamp device, the combination of a body, a plunger with anopening countersunk at its outer end slidably'mounted therein, aretaining member Ycomprised of yspaced parallel legs mountedlongitudinally of the body, the inner ends of said legs being disposedlongitudinally in the opening through the plunger and having headedportions adapted to engage in said countersunk end whereby to expandthem into engagement with the side walls of the countersunk opening.

'7. In a sheet metal fastener having a thimbleshaped body the closed endof which is centrally perforated, a plunger comprising apair-of ngersseated in the body perforation, a shouldered sleeve encompassing the`inner end of the p1unger, and means for spreading the iingers so as tolock them in position Within the sleeve.

FRANK C. WALLACE.

